It is a remarkable fact, suggestive of promising new search directions, that both the two latest additions
to the SM spectrum of particles have properties somewhat unusual for—though
not inconsistent with—the low energy effective field theory (EFT) paradigm,
according to which the SM would be accurate only up to a new
physics scale \(\Lambda \) , higher than the electroweak scale \(v_W\simeq 246\)  GeV.
The mass of the top quark (\(m_t\sim 173\)  GeV) is orders of magnitude larger than that of other fermions,
which in the SM context implies that its Yukawa coupling is comparatively large—so much so that its
effects in radiative (quantum) corrections might be invoked as
a possible cause for the vacuum instability that triggers electroweak symmetry breaking (EWSB).
Conversely, naive dimensional analysis (NDA) arguments suggest the mass \(m_h\)  of the Higgs boson
should be sensitive to \(\Lambda \) , which
indirect and direct searches at the Large Hadron Collider (LHC)
put in the multi-TeV range. But, experimentally,
\(m_h\simeq 125\)  GeV [1]}, [2]},
leading to the little hierarchy \(m_h \ll \Lambda \) .
These two observations suggest that Higgs and top physics might
be sensitive to new physics, and motivate many proposals for
extensions of the standard model, including the one
we will focus on in the following.
